This invention relates generally to a process control system for newspaper printing, and more specifically to a process control system for newspaper printing in which a press control subsystem and other control subsystems are linked with a production process control subsystem by means of a ring-shaped data highway network so that the entire newspaper printing system is supervised and control by the process control system.
Automation of the newspaper printing system begins with the automation of individual pieces of equipment such as the paster, the counter/stacker, and then evolves into the automatic soiled copies ejector and the automatic newspaper mailing line by organically connecting these "points" with a "line" (i.e., automation achieved by connecting individual devices into a continuous process line).
The Automated Newspaper Printing and Mailing System completed in Nihon Keizai Shinbun's Osaki Plant (Chiyoda Sogyo) in 1973 is an integrated control system for totally controlling the entire processes ranging from printing to shipment by means of a computer. This system, which is also called the NPC (Newspaper Plant Computerized System) that is a technological breakthrough representing a departure from the concept limited to "points" to the concept embracing "surfaces." The concept of computer control system is now further evolving into that of a total system embracing "three-dimensional" characteristics.
Formulation of the aforementioned total control system requires a data processing system in which a group of subsystems requiring high-speed, real-time processing, such as the press control department, the printing plate transportation control subsystem, the sorting and delivery control subsystem and the truck yard bundle sorting control subsystem; a group of subsystems that permit processing at relatively low speed, such as the newsprint roll storage control subsystem and the mail-room materials supply control subsystem; a group of subsystems that permit off-line processing, such as the materials and maintenance control subsystem; a group of subsystems that involve the processing of command information, such as the circulation control sub-system; and a production process control system that supervises and controls the subsystem group requiring high-speed, real-time processing and the subsystem group that permits relatively low-speed processing perform the individual processing given to each of them by means of either of a processor or an intelligent input/output unit incorporated in each of these control subsystems.
In such a case, an important problem is how to link a plurality of press control and other control subsystems with the production process control system. Particularly, a parallel data transmission among a multitude of processors could increase the number of signal lines. A data transmission in a bit-serial fashion, on the other hand, could hamper real-time processing. Furthermore, if information is exchanged between the production process control system and a subsystem group allowing off-line processing or a subsystem group involving the processing of command information, using a transmission route in common with the information transmission between the production process control subsystem and a subsystem group requiring real-time processing, an unexpected trouble might result in the latter information transmission.
In automating the conventional system, a system concept has heretofore been employed in which the number of newspaper copies and addresses (hereinafter referred to as address labels) are prepared off-line in the circulation control subsystem; and the sorting and delivery control subsystem and the press control subsystem perform processing operations on the basis of the information contained in the address labels. In formulating a total control system, however, it is desired that the newspaper printing system can flexibly and quickly cope with day-to-day or hourly changes in the number of copies in circulation, rather than resorting to the address labels prepared off-line.